Improved jibe-alarm



@with giants' @anni @titre ISAAC T. PEASE, OF THOMPSON VILLE, CONNECTICUT.

Letters Patent No. 72,672, dated lecember 24,1867.

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TO ALL WHOM IT MAY CON CERN:

' Be it known that I, ISAAC T. PEASE, of Thompsonville, in the town of Eneld, county ofl Hartford, and State of Connecticut, have invented a new and useful Improvement in Fire-Alarms; and I do hereby declare that the following is a full, clear, *and exact description of the same, reference being had to the accompanying drawings, and to the lettersl 'of reference marked thereon. -v

Figure 1 shows a front view of the improved fire-alarm.

Figure 2 shows a top view of the same. I

My invention consists in so constructing a se1f-acting {ire-alarm, intended to be placed in any part cfa building, that, by thecunequal expansion of ltwo metals joined together in strips, the increased temperature of a room in which a re takes place shall operate in sucha manner as to release a catch and give an alarm, by means of a common'alarm-contrivance, or-by ringing a bell. v

A is the frame to which the diiierent parts of the apparatus are attached. B B are the expansionbar, composed of strips of ironvand brass, or any' other metals having unequal degrees of expansion by heat. vThe metal having the leastl expansion is placed upon the outside of the curve at B, so that a rise of temperature shall expand the inside of the curve more than the outside, and thereby causing the parts at b b to be further apart the higher the temperature. This causes the wholebar between C and n to be considerably lengthcned,

by a slight rise in temperature.

One end ofthe bar B is ixed to the frame A at 0, whilethe other end is free to move. To this free end is attached, by the nut n, a regulating-screw, S, which can be set out or in to let off the alarm at diierent temperatures. It also passes through a guide, Upon'this screw rests the lever D, which has a nick, d, to hold the arm E 'of the hammer H, which strikes uponthe alarm-bell F F.' I v G is a common alarm-movement, such as is ordinarily used in alarm-clocks. It is composed of a spring, I, which is wound-up by a key, and a train of Wheels, which act upon the hammer H as soonv as it is 'released from raisesiit up to release the pin q from' the arm K. v

i The axis L carries the threearms K, L, M. L isanarm, to which a. bell-wire can be attached to lead'to any part of the building where it is desired to give the alarm. The arm M is connected by the -link N to the spring O, which draws the arm M forcibly back when .the arni K is released from the pin g. If it is desired to pull the arm L in the opposite direction, the arm M is attached by the link to the spring P instead of 0.

TheY operation of my'invention is as follows: The alarm is setby winding up the spring I, and setting the the detent in the lever D.- Upon one of the wheels of the train is the-pin p, which operates the lever J, andl lever K so that itshall rest upon the ping. The lever D is then placed in its proper position upon the screw S, the arm E being'placed inthe nick d, and the screw S adjusted to let oii` the lever at the desired temperature. This is done by a gauge introduced between the head of the screw and the nut n. When a ire occurs, and the temperature of the 'room rises to the height to which the apparatus is set, the bar Dis released by the lengthening of the bar B B, and the alarm rings. The pinp pushesup the lever J, and releases the lever-arm K, so that flies back by the action of' the spring O, and pulls a bell or other alarm in a distant room.

What I claim as my invention, anddesire to secure by Letters Patent, is 1. The curved expansion-bar B, v composed of two metals, of different rates of expansion by heat, and the adjustable screw S, when constructed1and arrangedv substantially as herein described, for the purpose of a re-alarm. 4

2. The combination of the bar B, the screw S, the alarm-movement G, the lever J, the leversK and L, or their equivalents, substantially as herein described. l

` ISAAC T. PEASE. Witnesses:

Hnnnrli. Bowan, Turc. G, ELLIS. 

